2 

3 


THE   TYPE    OP   THE   PANAMA   CANAL 


BY  C.  B.  GRUNSKY      ^655" 
'.  ) 


[Reprinted  from  the  POPULAR  SCIENCE  MONTHLY,  May,  1909] 


[  Kcprinled    from    TIIK    Poi-i  I.AK    Sc  IK\<  i:    MO.NTIIIV.    M;i\.    I'.HC.I. 


THE  TYPE  OF  THE  PANAMA  CANAL 

By  C.  E.  GRUNSKY 

MKMliKR    OF    THE    ISTHMIAN    CANAL    COMMISSION    OF     1  !>H  I 

T~T~XT)ER  the  law  of  June  28.,  1902,  generally  referred  to  as  the 
Spooner  act,  which,  authorizes  the  construction  of  an  inter- 
oceanic  canal  President  Roosevelt  appointed,  in  March,  1904,  the  fol- 
lowing commissioners:  Rear  Admiral  John  G.  Walker,  U.  S.  Navy 
(retired),  chairman;  Major  Genl.  Geo.  W.  Davis,  U.  S.  Army  (retired) ; 
Col.  Frank  J.  Hecker,  of  Detroit;  Major  Benjamin  M.  Harrod,  civil 
engineer  of  New  Orleans ;  Professor  Willam  H.  Burr,  of  Columbia  Uni- 
versity, New  York;  Wm.  Barclay  Parsons,  of  New  York;  and  the 
writer,  of  San  Francisco. 

The  Spooner  act  empowers  the  president  to  purchase  the  canal 
properties  upon  the  Panama  route  at  a  cost  not  exceeding  $40,000,000, 
or,  in  the  event  of  failure  to  do  this,  to  enter  into  negotiations  with 
the  republics  of  Costa  Rica  and  Nicaragua  for  a  right  of  way  on  what 
is  commonly  known  as  the  Nicaragua  route. 

Provision  was  made  for  the  prosecution  of  the  work  of  canal  con- 
struction by  the  president,  acting  through  and  with  the  aid  of  a  canal 
commission.  An  appropriation  of  $10,000,000  was  carried  by  the  act 
for  use  upon  either  of  the  two  routes,  and  Congress  was  pledged  to 
make  additional  appropriations  as  required  up  to  $135,000,000  in  case 
the  Panama  route  was  adopted  and  not  to  exceed  $180,000,000  for 
work  on  the  Nicaragua  route.  The  secretary  of  the  treasury  is  author- 
ized to  borrow  from  time  to  time,  as  funds  may  be  required,  the  sum 
of  $130,000,000,  issuing  therefor  coupon  or  registered  thirty-year  bonds 
in  such  form  as  he  may  prescribe,  redeemable  after  ten  years.  1  tearing 
interest  at  two  per  centum  per  annum. 

The  passage  of  the  Spooner  act  by  Congress,  followed  the  submis- 
of  a  report  by  the  canal  commission  of  1899-1901,  which  recom- 

VOL.  L.XXIV. — 27.  417 


THE   POPULAR    SCIENCE   MONTHLY 


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THE    TYPE    OF    THE   PANAMA    CANAL  41 9 

mended  the  acquisition  by  the  United  States  of  the  rights  and  prop- 
erties of  the  New  Panama  Canal  Company.  This  recommendation  was 
the  direct  result  of  an  offer  of  the  canal  company  to  sell  all  its  rights 
and  properties  for  the  sum  of  $40,000,000.  The  actual  transfer  of  the 
canal  properties  to  the  United  States  took  place  on  May  4,  1904. 

The  great  engineering  question  before  the  commission,  above 
named,  related  to  the  type  of  canal.  Should  the  canal  be  built  at  sea- 
level  or  should  it  cross  the  backbone  of  the  isthmus  at  the  elevation 
suggested  by  the  investigating  commission  of  1899-1901,  and  appar- 
ently contemplated  by  the  Spooner  act,  with  a  summit  level  at  85  feet, 
or  should  it  be  a  lock  canal  with  some  other  elevation  of  its  summit 
section?  This  question  and  the  administration's  course  in  setting 
aside  the  recommendation  of  a  majority  of  the  board  of  consulting 
engineers  and  adopting  the  plan  of  a  lock-canal  with  a  summit  at  the 
elevation  suggested  by  the  commission  of  1899  and  advocated  by  the 
minority  members  of  the  board  of  engineers  are  still  fruitful  of  dis- 
cussion. 

A  review  of  the  proceedings  leading  to  the  solution,  and  a  presenta- 
tion of  some  of  the  physical  features  of  the  problem,  as  disclosed  by 
the  proceedings,  may  prove  an  aid  to  a  better  understanding  of  the 
present  situation. 

Relating  to  the  kind  of  canal  to  be  constructed  the  law  provides : 

The  President  shall  then,  through  the  Isthmian  Canal  Commission  .  .  . 
cause  to  be  excavated,  constructed  and  completed,  utilizing  to  that  end,  as  far 
as  practicable,  the  work  heretofore  done  by  the  New  Panama  Canal  Company, 
of  France,  and  its  predecessor  company,  a  ship  canal  from  the  Caribbean  Sea 
to  the  Pacific  Ocean.  Such  canal  shall  be  of  sufficient  capacity  and  depth  as 
shall  afford  convenient  passage  for  vessels  of  the  largest  tonnage  and  greatest 
draft  now  in  use,  and  such  as  may  reasonably  be  anticipated,  and  shall  be 
supplied  with  all  necessary  locks  and  other  appliances  to  meet  the  necessities 
of  vessels  passing  through  the  same  from  ocean  to  ocean.  .  .  . 

It  was  recognized  by  the  commission  of  1904  that  under  the  Spooner 
act  as  quoted,  a  departure,  to  some  extent  at  least,  from  the  project 
which  the  earlier  commission  had  outlined  as  a  basis  for  comparative 
cost  estimates  was  authorized  and  proper.  It  was  incumbent  upon  the 
commission  to  determine  whether  a  canal  with  summit  level  at  80  or 
60  or  30  feet  would  not,  all  things  considered,  be  better  than  the  canal 
with  summit  level  at  85  feet.  It  was  therefore  necessary  to  regard  the 
entire  question  of  type  of  canal  an  open  one  to  be  solved  by  the  selection 
of  that  type  and  that  summit  elevation  which  would  best  fulfill  all 
requirements.  It  was  realized  that  this  question  required  careful  con- 
sideration from  every  standpoint,  particularly  in  relation  to  its  service- 
ability, to  time  required  for  construction,  to  first  cost  and  to  the  cost 
of  operation  and  maintenance  with  due  regard  to  the  importance  of 
early  completion,  and  reliability  of  service  after  completion. 

In  entering  upon  a  preliminary  discussion  of  these  matters  the  lack 


420  THE   POPULAR    SCIENCE   MONTHLY 


SEA<;OIXG  SUCTION  DREDGE  Ancon  TAKING  ON  COAL  NEAR  DRY  DOCK  AT  CRISTOBEL. 
This  and  other  photographs  are  from  the  Annual  Reports  of  the  Commission. 

of  adequate  data  was  sorely  felt  by  the  members  of  the  commission  and 
it  was  soon  found  that  no  satisfactory  conclusion  could  be  reached  with- 
out supplementing  by  additional  exploration  with  the  auger  and  other- 
wise, the  information  disclosed  by  records  of  surveys,  borings  and 
shafts,  which  had  been  made  by  the  engineers  of  the  French  canal  com- 
panies. There  had  been  no  explorations  to  sea-level  by  shaft  or  by 
borings  in  the  central  sections  of  the  canal  yet  this  information  was 
now  of  paramount  importance  for  the  determination  of  safe  slopes  for 
the  sides  of  the  deep  cuts.  In  the  absence  of  such  information  no  satis- 
factory conclusion  could  be  reached  relating  to  the  amount  of  material 
that  would  have  to  be  excavated  to  maintain  a  great  open  cut  at  Cule- 
bra.  The  side  slopes  of  this  cut  must  be  so  flat  that  they  will  stand 
permanently.  They  should  be  as  steep  as  they  can  safely  be  held  in 
order  that  the  quantity  of  excavation  may  not  be  unnecessarily  in- 
creased. For  the  solution  of  this  problem,  it  was  necessary  to  know  not 
only  the  character  of  all  material  to  be  encountered  down  to  sea-level, 
but  to  a  depth  of  over  40  feet  below  sea-level.  Incomplete  or  unre- 
liable data  would  throw  more  or  less  doubt  upon  the  conclusions 
reached. 

The  commission  of  1904,  therefore,  entered  at  once  upon  the  col- 
lection of  additional  data  and  hoped  to  be  able  to  reach  an  intelligent 
conclusion  relating  to  the  type  of  the  canal  at  an  early  date.  The 
published  proceedings  of  the  commission  show  that  on  December  8, 
1904,  seven  months  after  the  United  States  had  taken  possession  of 
the  canal  properties,  it  was  resolved  to  send  the  committee  on  engineer- 
ing, consisting  of  Professor  W.  H.  Burr,  Wm.  Barclay  Parsons,  and 
Major  B.  M.  Harrod  to  the  isthmus 


THE    TYPE    OF    THE   PANAMA    CANAL  421 

to  see  that  the  necessary  surveys  and  data  for  determining  the  type  of  canal 
have  been  completed  and  to  bring  the  same  to  Washington  to  be  laid  before 
the  commission;  and  that  the  committee  on  engineering  plans  shall,  if  possible, 
recommend  to  the  commission,  during  March,  various  plans  and  estimates  for 
the  several  types  of  canal,  so  that  the  commission  as  a  whole  may  determine 
the  same. 

The  writer  was  a  fourth  member  of  the  committee  on  engineering  plans. 

In  compliance  with  this  resolution  two  members  of  the  committee, 
Professor  Burr  and  Mr.  Parsons,  went  to  the  isthmus,  where  their 
deliberations  were  participated  in  by  General  Davis,  who  by  virtue  of 
his  station  on  the  isthmus  was  a  member  of  all  committees  there  in 
session.  Major  Harrod  did  not  accompany  the  other  members  of  the 
committee,  because  it  was  necessary  to  preserve  a  quorum  of  the  com- 
mission at  Washington  for  the  transaction  of  business. 

On  February  23;  1905,  the  committee,  having  returned  from  the 
isthmus,  made  a  report,  in  which  it  recommended  that  the  construc- 
tion of  a  breakwater  at  the  entrance  of  Limon  Bay  should  be  com- 
menced at  the  earliest  practicable  date;  that  the  harbor  at  Cristobal 
should  be  deepened  and  otherwise  improved;  that,  if  a  lock-canal  be 
constructed  the  summit  level  of  the  canal  should  not  exceed  60  feet; 
that  Chagres  River  should  be  controlled  by  a  dam  at  Gamboa;  and 
that  a  plan  for  a  sea-level  canal,  free  from  the  restriction  of  locks 
(except  a  tidal  lock  near  the  Pacific  Ocean)  should  be  adopted.  The 
committee  included  in  its  recommendations  150  feet  as  the  least  bot- 
tom-width of  the  canal  and  35  feet  as  the  least  depth,  suggesting, 
however,  that  estimates  be  also  made  to  cover  a  depth  of  -1-0  feet.  The 
committee  also  took  up  the  question  of  the  necessary  lock  dimensions, 
if  locks  be  required,  and  advocated  a  width  of  100  feet  and  a  usable 


OLD  FRENCH   LADDER  OR  ELEVATOR  DREDGE  DEEPENING   ENTRANCE   CHA.N.NKL  IN   THE 

PACIFIC  NEAR  LA  BOCA.     This  dredge  is  being  served  by  two  old  French 

self-propelling  hopper  barges,  known  as  "  clnpets." 


422 


TYPICAL  CROSS  SECTION  ADOPTED  BY  THE  BOARD  OF  CONSULTING  ENGINEERS  FOR 
THE  CULEBRA  CUT.     K.  54.41. 

length  of  1,000  feet,  but  with  intermediate  gates  to  conserve  time  and 
water.  The  committee  called  attention  to  the  increasing  difficulties  of 
constructing  a  dam  at  or  near  Bohio,  disclosed  by  additional  borings, 
and  condemned  as  impracticable  a  dam  at  Gatun  where  borings  to  172 
and  to  139  feet  below  sea-level  did  not  reach  bed-rock. 

The  data,  which  the  commission  had  instructed  the  committee  to 
bring  to  Washington,  were  not  submitted  with  the  report,  neither  did 
such  data  accompany  a  progress  report  of  the  chief  engineer,  Mr.  John 
F.  Wallace,  which  was  received  a  few  weeks  later.  The  type  of  canal 
was,  however,  quite  fully  discussed  by  Mr.  Wallace,  and  his  report  con- 
tained the  recommendation 

that  no  temporary  or  tentative  plan  be  adopted  that  will  interfere  with  the 
final  adoption  of  the  "  sea-level  plan,"  which  it  is  hoped  will  ultimately  receive 
the  favorable  consideration  of  the  commission. 

The  committee  report,  however,  brought  before  the  commission  a 
definite  recommendation,  relating  to  the  type  of  the  canal.  In  the 


& 

Total  Amount   of   Excavation    required    May  1,  1904: 
l«,000',000    Cubic    Yards. 

FIG.  1.  PROGRESS  OF  EXCAVATION  ON 
THE  PANAMA  CANAL  UNDER  THE  UNITED 
STATES,  AS  COMPARED  WITH  TOTAL  EX- 
CAVATION REQUIRED. 


Total  Estimated  Excavation,  -including 
French- ISZ.OOO, 000  Cv. Yds. 


FIG.  '2.  DIAGRAM  SHOWING  RELATION 
OF  FRENCH  AND  AMERICAN  EXCAVATION 
ON  PANAMA  CANAL  TO  TOTAL  ESTIMATED 
AMOUNT. 


THE    TYPE    OF    THE   PANAMA    CANAL  423 

absence  of  the  data  necessary  to  reach  a  final  conclusion  on  this  point, 
and  in  view  of  the  fact  that  no  embarrassment  would  result  from  a  de- 
liberate weighing  of  all  the  facts,  the  writer,  though  with  a  pronounced 
leaning  toward  the  sea-level  type,  could  not  see  his  own  way  clear  to  an 
immediate  concurrence  in  the  conclusions  of  the  committee.  There 
was  nothing  convincing  either  in  the  report  of  the  chief  engineer  nor 
in  the  report  of  the  committee  relating  to  quantity  of  material  to  be 
excavated  nor  in  relation  to  probable  cost.  The  writer  did  not  then 
believe,  nor  does  he  now  believe,  that  the  steep  slopes  where  the  cut  is 
deepest,  as  suggested  by  the  committee,  nor  as  incorporated  in  the  plans 
now  being  carried  out,  can  be  adhered  to.1  There  will  have  to  be  taken 
out  ultimately  very  much  more  material  than  heretofore  assumed  at 
Culebra.  This  fact  coupled  with  the  concentration  of  the  great  mass 
of  the  excavation  in  a  relatively  short  central  section  of  the  canal,  which 
rendered  preliminary  estimates  of  time  and  cost  of  the  removal  of  this 
^material  uncertain,  was  a  factor  that  could  not  be  ignored.  When, 
therefore,  at  a  meeting  of  the  commission  in  March,  1905,  it  was  pro- 
posed by  Major  Harrod  that  the  recommendation  of  the  committee  be 
adopted  and  that  the  commission  decide  in  favor  of  the  sea-level  canal 
the  writer  was  not  prepared  to  go  so  far  and  the  committee  report  was 
referred  to  the  committee  on  engineering  plans,  of  which  he  was  a 
member,  for  further  consideration. 

From  these  facts,  as  recorded  in  the  printed  proceedings  of  the 
canal  commission,  it  might  be  inferred  that  at  that  time  Major  Harrod 
was  in  favor  of  the  sea-level  type  of  canal  and  that  the  writer  favored 
the  lock  type.  But  the  writer's  stand  was  taken,  as  explained,  to  pre- 
vent action  based  on  inadequate  data,  while  Major  Harrod  is  found 
eight  months  later  among  the  members  of  the  second  canal  commission 
who  determined  that  the  lock  plan  of  canal,  as  recommended  by  the 
minority  of  the  board  of  consulting  engineers,  is  the  one  that  should 
be  carried  out.  And  now  the  writer,  after  having  had  several  years 
more  time  for  reflection,  and  in  the  light  of  such  additional  informa- 
tion as  has  come  to  hand,  is  not  yet  convinced  that  the  wisest  course 
was  pursued  by  the  later  commission,  by  the  secretary  of  war,  by  the 
president  and  by  congress  when  the  findings  of  the  majority  of  the 
board  of  consulting  engineers,  eight  to  five,  were  disregarded  and  the 
plans  for  a  lock-canal  project,  as  recommended  by  the  minorit}r,  were 
adopted. 

Before  the  committee  on  engineering  plans  made  a  report  the 
Walker  commission  was  superseded  by  the  commission  of  1905,  whose 
powers  were  concentrated  in  an  executive  committee  of  three,  at  the 

1  Since  this  article  was  written  information  has  been  received  that  there  has 
been  much  flattening  of  slopes.  The  standard  section  as  shown  in  the  illustra- 
tion elsewhere  presented  is  therefore  no  longer  strictly  typical  of  the  section  to 
which  the  canal  will  be  finished. 


424 


THE   POPULAR   SCIENCE   MONTHLY 


VIEW    IX    CULEKHA    CUT,    XEAR    EMPIRE,    LOOKIXG    SOUTH. 

head  of  which,  with  dominating  influence  in  the  commission's  executive 
affairs,  was  Mr.  T.  P.  Shonts. 

This  commission  was  appointed  on  April  3,  1905.  Two  months 
later  President  Eoosevelt  named  a  board  of  consulting  engineers,  to 
whom  he  submitted  the  question  of  canal  type.  Thirteen  engineers 
accepted  the  invitation  to  participate  in  the  deliberations  of  this  board 
of  engineers. 

The  board,  as  finally  constituted,  consisted  of :  Geo.  W.  Davis,  Major 
General  U.  S.  Army  (retired),  chairman;  Alfred  Noble,  chief  engineer 
of  the  East  River  Division  P.,  N.  Y.  &  L.  I,  R.  "R. ;  Wm.  Barclay  Par- 
sons, chief  engineer  of  the  New  York  Subway ;  Wm.  H.  Burr,  professor 
of  civil  engineering,  Columbia  University ;  Henry  L.  Abbot,  Brigadier 


STEAM  SHOVELS  LOADING  LEDGERWOOD  FLATS  ox  EAST  SIDE  OF  CULEBRA  CUT 
JUST  SOUTH  OF  GOLD  HILL. 


THE    TYPE    OF    THE   PANAMA    CANAL  425 

General  TJ.  S.  Army  (retired) ;  Frederic  P.  Stearns,  chief  engineer  of 
the  Metropolitan  Water  and  Sewerage  Board,  Boston ;  Joseph  Kipley, 
general  superintendent  of  the  St.  Mary's  Falls  Canal ;  Isham  Randolph, 
chief  engineer  of  the  Sanitary  District,  Chicago;  Wm.  Henry  Hunter, 
chief  engineer  of  the  Manchester  Ship  Canal;  Eugen  Tincauzer,  Konig- 
lich  Preussischer  Regierungs-und-Baurath,  Konigsberg,  Germany; 
Adolphe  Guerard,  inspector  general  des  Ponts  et  Chaussees,  France; 
E.  Quellennec,  chief  engineer  des  Ponts  et  Chaussees  and  consulting 
engineer  of  the  Suez  Canal  Company,  France;  and  J.  W.  Welcker, 
Hoofdingenieur,  Directeur  van  den  Ryks-Waterstaat,  The  Netherlands. 

On  this  board  of  engineers  were  the  three  members  of  the  first 
canal  commission,,2  General  Davis,  Professor  Burr  and  Mr.  Parsons, 
who  a  few  months  before  had  submitted  a  recommendation  favoring  a 
sea-level  canal.  Other  members  of  the  board  were  known  to  favor  a 
lock  canal.  The  members  of  the  board  therefore  naturally  fell  into  two 
groups  of  which  one  was  friendly  to  the  sea-level,  the  other  to  the  lock 
type  of  canal,  and  to  the  committees  appointed  from  these  groups  was 
assigned  the  task  of  discussing  the  canal  problem  from  the  two  diverg- 
ent standpoints.  The  board  as  a  whole,  however,  passed  on  certain 
features  in  order  that  the  conclusions  thus  reached  might  serve  as  a 
guide  in  determining  other  features  of  the  projects.  Thus  it  was  re- 
solved that  locks  should  have  a  usable  length  of  1,000  feet,  a  width  of 
100  feet  and  a  depth  of  40  feet.  The  board  determined,  too,  upon  the 
type  and  dimensions  of  the  canal  section  which  should  be  made  the 
basis  of  a  comparison  of  cost  estimates. 

The  consulting  engineers  visited  the  isthmus  and  thus  learned 
much,  by  personal  observation,  of  the  conditions  under  which  the  canal 
work  must  be  prosecuted. 

As  a  result  of  their  studies  the  members  of  the  lock-canal  committee 
of  the  board  of  engineers  submitted  four  projects.  Two  of  these  were 
for  a  canal  with  a  summit  level  at  60  feet  and  the  other  two  for  a  canal 
with  its  highest  section  at  85  feet. 

Other  projects  for  the  lock-type  of  canal  were  presented  by  Mr. 
Lindon  W.  Bates,  by  Mr.  P.  Bunau-Varilla  and  by  Major  C.  E.  Gil- 
lette, of  the  engineer  corps  of  the  U.  S.  Army.  Mr.  Bates  presented 
three  projects  with  a  preference  expressed  for  a  plan  including  a  terminal 
lake  at  each  end  of  the  canal,  of  which  the  lake  at  the  Atlantic  end  was 
to  be  formed  by  a  dam  at  Mindi  and  the  lake  at  the  Pacific  end  by 
dams  from  Ancon  to  Sosa  Hill  and  from  Sosa  Hill  across  the  Rio 
Grande.  Under  this  project  there  would  also  be  an  intermediate  lake, 
formed  by  a  dam  across  the  Chagres  River  at  Bohio.  The  summit  level 
suggested  was  62  feet. 

2  Of  the  other  members  of  the  first  commission  Admiral  Walker  had  re- 
turned to  private  life.  Major  Harrod  had  been  named  on  the  second  commission 
and  the  writer  had  accepted  the  position  of  chief  consulting  engineer  in  the 
Eeclamation  Service  under  the  Secretary  of  the  Interior. 


426 


THE    POPULAR    SCIENCE    MONTHLY 


LAS  CASCADAS  SLIDE,  CULKKRA  DIVISION,  APRIL,  1908.     AREA  OF  SLIDE,  5,433  SQUARE 

YARDS.     Estimated  amount  of  material  in  motion,  100,000  cubic  yards. 

This  slide  started  in  the  dry  season  and  extended  back  230  feet  from 

the  edge  of  cut  and  to  within  50  feet  of  the  crest  of  the  hill. 

Mr.  Bunau-Varilla,  a  civil  engineer  who  was  at  one  time  chief 
engineer,  of  the  Panama  Canal  Company,  proposed  a  project  with  a 
summit  level  at  130  feet;  but  with  all  locks  so  arranged  that  there 
could  be  a  gradual  progress  of  excavation  and  deepening  of  the  summit 
level  with  a  successive  cutting  out  of  locks  until  finally  the  lock  canal 
was  converted  into  a  sea-level  canal. 

Major  Gillette  advocated  a  lock  canal  with  its  highest  section  at  100 
feet  above  sea-level. 

The  sea-level  canal  committee  of  the  board  of  engineers  reported  in 
favor  of  a  canal  40  feet  deep,  with  a  bottom  width  of  150  feet  in  earth, 
and  side  slopes  adjusted  to  the  nature  of  the  ground  so  as  to  give  a 
surface  width  of  302  to  437  feet.  The  bottom  width  in  rock  was 
to  be  increased  to  200  feet  and  the  surface  width  in  rock  was  to  be 
208  feet.  At  the  Pacific  end  the  canal  was  to  be  protected  by  a  tidal 
lock  located  between  Ancon  and  Sosa  hills.  The  plans,  as  proposed  by 
the  committee,  included  a  clam  at  Gamboa  across  Chagres  River  of 
either  masonry  alone  or  of  earth  and  masonry  combined.  This  dam 
was  necessary  for  the  control  of  the  river. 

The  dimensions  of  the  canal  of  the  committee  project  at  the  point 
of  deepest  cutting  near  Culebra  are  as  follows :  Bottom  width,  200  feet ; 
the  banks  to  have  a  batter  of  1  in  10  rising  from  the  bottom  to  a  berm 
10  feet  above  the  water  surface;  the  berm  to  be  45  feet  wide  (according 
to  diagram;  50  feet  according  to  text  of  report)  ;  then  a  succession  of 
bank  slopes  with  a  batter  of  1  in  4  and  a  rise  each  of  30  feet,  one  above 
the  other,  with  intermediate  berms  each  12^  feet  wide  up  to  the  rock 
line — shown  by  a  diagram  for  the  point  known  as  Kilometer  54.41  in 


THE    TYPE    OF    THE   PANAMA    CANAL  427 

Culebra  cut  at  about  170  feet  above  tbe  water  surface — thence  to  the 
natural  surface  with  a  rise  of  one  foot  in  two. 

In  the  course  of  its  deliberations  the  board  of  engineers  passed 
favorably  upon  the  feasibility  of  a  canal  of  either  the  lock  or  sea-level 
type.  It  determined  that  a  lock  canal  with  summit  level  at  60  feet 
should  be  the  basis  of  compaiison  of  the  lock  with  the  sea-level  type.  It 
reached  the  conclusion  that  about  10  to  11  years  should  be  the  time 
assumed  to  be  necessary  for  the  construction  of  a  lock  canal,  with  sum- 
mit level  at  GO  feet,  and  about  12  to  13  yea'rs  for  the  construction  of  a 
sea-level  canal. 

The  quantity  of  material  of  all  kinds  to  be  excavated  in  construct- 
ing a  sea-level  canal  was  estimated  at  231,026,000  cubic  yards,  and  the 
estimated  cost  of  making  the  excavation  was  $183,136,000. 

Among  the  important  considerations  bearing  upon  the  selection  of 
the  best  canal  type  the  board  of  consulting  engineers,  as  noted  in  the 
majority  repoit,  says: 

The  canal  will  provide  the  one  great  maritime  highway,  not  between  seas, 
but  between  oceans;  not  for  countries,  but  for  continents.  The  vastness  of  the 
interests  to  be  served  by  the  canal,  many  of  which  interests  now  wait  for  their 
development  on  the  construction  of  the  waterway,  demands  that  the  canal  shall, 
when  opened  for  traffic,  be  of  the  type  which  will  most  perfectly  fulfil  the 
purposes  which  the  waterway  is  intended  to  accomplish. 

First  and  foremost  it  is  essential  that  the  Panama  Canal  shall  present  not 
merely  a  means  of  interoceanic  navigation,  but  a  means  of  safe  and  uninter- 
rupted navigation  on  which  no  special  hazards  will  be  encountered  by  and  no 
vexatious  delays  will  be  occasioned  to  the  vessels  which  will  traverse  it.  It  is 
therefore  evident  that  the  canal  ought  to  be  formed  in  such  manner  that  the 
course  thereof  shall  be  free  from  all  unnecessary  obstructions,  and  that  no 
obstacles  should  be  interposed  in  that  course,  whether  temporary  or  permanent, 
which  would  by  their  very  nature  be  an  occasion  of  peril  and  of  detention  to 


MATERIAL  ON  THE  COKOZAL  DUMP. 


428  THE   POPULAR    SCIENCE   MONTHLY 

passing  vessels,  and  more  particularly  to  vessels  of  the  great  size  which  the 
Panama  Canal  is  designed  to  accommodate. 

The  board  is  of  opinion  that  this  consideration  should  be  of  determining 
force  in  respect  to  the  type  of  canal  to  be  adopted,  and  that  it  should  lead  to 
rejection  of  all  proposed  plans  in  which  lift-locks,  whether  few  or  many,  form 
the  principal  or  dominating  features,  and  consequently  to  the  acceptance  of  the 
sea-level  plan  as  the  only  one  giving  reasonable  assurance  of  safe  and  uninter- 
rupted navigation. 

The  majority  then  set  forth  that  no  canal  with  locks  can  fulfil 
these  requirements  and  that  the  sea-level  canal  is  the  only  type  of  canal 
that  can  give  reasonable  assurance  of  safe  and  uninterrupted  naviga- 
tion. They  refer  to  three  accidents  in  the  preceding  nine  years  arising 
from  collisions  between  steamers  and  lock  gates  on  the  "  Soo,"  and  to 
three  accidents  of  a  like  nature  on  the  Manchester  Canal,  and  to  the 
disastrous  results  that  would  have  followed  such  accidents  at  the  locks 


TRESTLE  DUMP  JUST  OUTSIDE  OF  EAST  TOE  OF  THE  SOSA-COEOZAL  DAM. 
Ancon  Hill  and  Ancon  Hospital  buildings  in  the  background. 

of  larger  dimensions  and  higher  lift  on  the  Panama  Canal.  They 
placed  the  estimated  cost  of  a  sea-level  canal  at  less  than  $250,000,000, 
and  thought  that  it  could  be  completed  in  twelve  to  thirteen  years. 
They  strongly  condemned  any  provisional  treatment  such  as  the  con- 
struction of  a  lock  canal. 

It  is  interesting  to  find  among  these  members  Mr.  Hunter,  the  chief 
engineer  of  the  Manchester  Ship  Canal  (which  is  a  lock  canal),  who  in 
a  convincing  statement  explains  why,  although  as  a, member  of  the 
Comite  Technique,  he  favored  the  lock  canal  as  best  suited  to  the  con- 
ditions under  which  the  New  Panama  Canal  Company  was  operating, 
he  is  now  in  favor  of  the  sea-level  canal. 

As  an  offset  to  the  recommendation  of  the  majority,  a  minority  of 
five  members,  Noble,  Abbot,  Stearns,  Bipley  and  Eandolph  favored  a 
lock  canal  for  the  following  reasons : 


THE    TYPE    OF    THE   PANAMA    CANAL  429 

Greater  capacity  for  traffic  than  afforded  by  the  narrow  waterway  proposed 
by  the  board. 

Greater  safety  for  ships  and  less  danger  of  interruption  to  traffic  by  reason 
of  the  wider  and  deeper  channels  which  the  lock  canal  makes  possible  at 
small  cost. 

Quicker  passage  across  the  Isthmus  for  large  ships  or  a  large  traffic. 

Materially  less  time  required  for  construction. 

Materially  less  cost. 

The  project  recommended  by  the  minority,  which  is  the  project  as 
now  being  carried  out  (except  for  an  enlargement  of  the  locks,  a  change 
of  lock  locations,  and  the  abandonment  of  the  proposed  dams  on  both 
sides  of  Sosa  Hill  at  the  Pacific  end  of  the  canal),  includes  a  dam  at 
Clatun,  but  none  at  Bohio,  and  no  dam  at  Gamboa.  The  locks  were  to 
be  95  feet  wide,  900  feet  long,  and  the  depth  of  water  was  to  be  40 
feet.  The  summit  level  was  fixed  at  85  feet. 

Under  the  minority  plan  there  were  to  be  at  the  Pacific  end  of  the 
canal  duplicate  locks  of  one  lift  of  31  feet  each,  and  twin  locks  in  flights 
of  two  at  Sosa  Hill. 

The  time  required  to  construct  the  lock  canal  was  estimated  by  the 
minority  at  about  six  years  less  than  would  be  required  for  a  sea-level 
canal,  and  the  cost  of  the  canal  is  estimated  by  them  at  $139,705,000. 
They  say  in  their  report : 

The  greater  cost  of  the  proposed  sea-level  canal — upward  of  $100,000,000 
more  than  that  of  the  lock  canal  herein  advocated — is  not  a  trifling  sum  even 
for  the  resources'  of  the  United  States.  If  such  an  outlay  is  incurred  a  greatly 
superior  waterway  should  be  obtained  or  the  expenditure  will  be  unwise  and  the 
result  discreditable. 

The  minority  then  present  their  views  at  length,  calling  attention 
to  the  small  risk  of  injury  to  a  well-equipped  canal  lock;  to  the  equal 
facility  of  protecting  the  canal  against  injury  in  time  of  war,  no  matter 
what  its  type ;  to  the  greater  liability  of  delay  and  injury  to  shipping  in 
traversing  artificial  channels  at  considerable  speed  than  in  moving 
slowly  under  perfect  control  through  locks;  to  the  greater  speed  at 
which  the  open  water  above  the  locks  can  be  navigated;  to  the  reduced 
time  that  will  be  required  in  the  passage  through  the  canal  with  locks ; 
to  the  greater  amount  of  traffic  that  would  at  the  outset  be  provided  for ; 
to  the  provisions  that  can  be  made  to  prevent  accidents  at  the  locks ;  to 
the  extraordinary  dimensions  proposed  for  the  earth  dams  at  Gatun 
and  at  Sosa  Hill;  to  the  fact  that  time  required  to  make  Culebra  cut 
and  to  construct  the  locks  is  about  the  same.  They  estimate  that  six 
years  less  time  will  be  required  to  build  the  lock  canal  than  to  build  a 
sea-level  canal. 

At  the  time,  January  10,  1906,  the  board  of  consulting  engineers 
submitted  their  majority  and  minority  reports  to  the  Isthmian  Canal 
Commission,  the  membership  of  the  commission  was  as  follows:  T.  P. 
Shonts,  chairman;  C.  E.  Magoon,  governor  of  the  Canal  Zone;  Rear 


43° 


THE   POPULAR    SCIENCE   MONTHLY 


Admiral  Mordecai  T.  Endicott,  civil  engineer,  U.  S.  Navy;  Brig.  Gen. 
Peter  C.  Hains,  corps  of  engineers,  U.  S.  Army  (retired)  ;  Col.  Oswald 
H.  Ernst,  corps  of  engineers,  U.  S.  Army  (retired)  ;  and  Benjamin  M. 
Harrod.  A  vacancy  in  the  commission  that  had  been  caused  by  the 
resignation  of  Mr.  John  F.  Wallace  had  not  been  filled. 

This  commission  determined  on  February  5,  1906,  by  a  vote  of 
five  to  one,  to  recommend  to  the  president  the  lock  canal  project  of  the 


LIMON  BAY  FROM  THE  DE  LESSEPS  HOUSE.     Sketched  April  10,  1904.     The  ships  at 
anchor  are  the  Newark,  the  Montgomery  and  the  Marietta,  all  of  the  U.  S.  Navy. 

minority  of  engineers.  The  dissenting  member  was  Admiral  Endicott, 
who  favored  the  adoption  of  the  sea-level  project. 

The  recommendation  of  the  commission  was  accompanied  by  a  re- 
port of  Mr.  John  F.  Stevens,  their  chief  engineer,  who  favored  the  lock- 
canal  plan. 

The  secretary  of  war  approved  the  recommendation  of  the  com- 
mission and  the  president  was  not  slow  in  acting.  On  February  19, 
1906,  the  reports  and  papers  were  transmitted  to  Congress  with  a  state- 
ment of  his  conclusions  that  the  type  of  canal  to  be  built  is  the  canal 
with  locks. 

On  June  21,  1906,  the  senate,  by  a  vote  of  36  toi31,  passed  an  act 
authorizing  the  construction  of  a  lock  canal.  This  act  was  a  few  days 
later  concurred  in  by  the  house  without  division.  It  provided 

That  a  lock  canal  be  constructed  across  the  Isthmus  of  Panama  connecting 
the  waters  of  the  Atlantic  and  Pacific  oceans,  of  the  general  type  proposed  by 
the  minority  of  the  board  of  consulting  engineers,  created  by  order  of  the 
President  under  date  of  January  24  (June  24),  1905,  in  pursuance  of  an  act 


THE    TYPE    OF    THE   PANAMA    CANAL  431 

entitled   "  An  act  to   provide   for  the  construction   of  a   canal   connecting  the 
waters  of  the  Atlantic  and  Pacific  Oceans,"  approved  June  28,  1902. 

It  has  already  been  stated  that  the  minority  of  the  board  of  engi- 
neers recommended  that  the  locks  be  made  95  feet  wide  with  a  usable 
length  of  900  feet.  The  canal  commission  determined  that  larger  locks 
would  be  desirable  and  fixed  the  width  at  100  and  the  usable  length 
at  1,000  feet.  This  action  did  not,  however,  satisfy  the  U.  S.  Navy. 
The  question  of  still  larger  locks  was  agitated  and  resulted  in  action 
by  the  naval  authorities  upon  whose  suggestion  it  was  finally  decided 
to  increase  the  width  of  the  locks  to  110  feet.  The  depth  of  water  in 
the  locks  is  to  be  about  41.5  feet;  this  will  be  the  depth  in  fresh  water 
which  will  be  equivalent  to  40  feet  in  salt  water. 

Since  the  final  and  specific  approval  of  the  lock-canal  plan  by  Con- 
gress all  the  work  on  the  isthmus  has  been  directed  to  the  rapid  con- 
struction of  this  type  of  canal.  Before  presenting  a  few  of  the  salient 
facts  relating  to  the  progress  which  has  been  made,  a  brief  review  will 
be  given  of  the  opinion  expressed  by  some  of  the  experts  whose  views 
were  considered  in  reaching  the  conclusion  that  under  all  the  circum- 
stances it  was  best  to  build  a  lock  canal. 

It  should  be  stated  in  this  connection  that  the  earlier  conclusion  of 
the  Comite  Technique,  which  was  an  advisory  body  to  the  New  French 
Canal  Company,  favoring  a  lock  canal,  can  be  given  but  little  weight, 
as  an  influence  upon  the  later  conclusion,  because  the  advice  of  that 
committee  was  given  to  a  private  company  operating  under  a  conces- 
sion with  a  time  limit,  and  it  was  compelled  to  give  paramount  weight 
to  the  financial  aspect.  A  canal  had  to  be  built  under  restrictions  of 
time  and  cost,  and  it  was  to  be  made  a  profitable  venture.  It  is  not  sur- 
prising, therefore,  that  under  the  new  conditions,  one  of  the  members 
of  that  committee,  Mr.  Hunter,  is  found  in  1905,  as  already  stated, 
among  those  who  advocate  the  sea-level  canal. 

Mr.  John  F.  Wallace,  a  past  president  of  the  American  Society 
of  Civil  Engineers,  who  was  called  from  the  position  of  chief  engineer 
and  manager  of  the  Illinois  Central  Eailroad  to  the  position  of  chief 
engineer  of  the  commission  of  1904  and  was  later  made  a  member  of 
the  commission  of  1905,  in  addressing  the  board  of  consulting  engineers 
poirited  out : 

That  the  most  desirable  transportation  routes  are  straight  and  level. 
Variation  from  the  ideal  may  become  necessary  to  overcome  obstacles  of  a 
physical,  financial  or  other  nature.  The  plan  usually  selected  is  the  one  in 
which  the  sum  obtained  by  adding  the  interest  on  cost  of  construction  to  the 
annual  cost  of  maintenance  and  operation  is  a  minimum.  In  the  case  of  the 
canal  the  feature  of  future  development  should  not  be  overlooked  and  any 
variation  from  the  ideal  of  a  straight  or  sea-level  canal  should  only  be  made 
after  the  most  mature  and  careful  consideration  and  for  the  gravest  of  reasons. 
Minor  deflections  from  a  straight  line  are  comparatively  immaterial  as  com- 
pared with  variations  of  levels. 


432 


THE   POPULAR    SCIENCE    MONTHLY 


THE   TYPE   OF   THE   PANAMA    CANAL  433 

Mr.  Wallace  formulates  certain  propositions  which  he  considers 
fundamental  and  others  which  are  essential  in  arriving  at  the  most 
desirable  plan  of  canal.  He  says  that  the  most  desirable  canal  is  the 
sea-level  canal  of  such  dimensions  as  would  afford  unrestricted  passage 
for  the  largest  vessels  afloat,  with  such  margin  for  increase  in  size  and 
draft  as  can  reasonably  be  anticipated,  making  allowance  for  unex- 
pected developments.  No  plan  should  be  adopted  that  would  prevent 
the  ultimate  construction  of  a  sea-level  canal  at  least  approximately 
approaching  to  the  final  idea  of  the  Straits  of  Panama.  Time  and  cost 
should  be  considered  to  the  extreme  limit  before  determining  upon  a 
plan  which  would  interfere  with  this  ultimately  desirable  accomplish- 
ment. It  is  highly  desirable  that  no  dams  should  be  constructed  the 
foundations  of  which  can  not  be  carried  to  bed  rock,  or  at  least  imper- 
vious curtain  connection  be  made  therewith.  No  high  dam  should  be 
constructed,  the  destruction  of  which,  by  accident  or.  design,  would  close 
navigation  through  the  canal  until  its  restoration.  If  it  is  absolutely 
essential  to  the  project  that  such  dams  be  constructed,  they  should 
retain  the  lowest  possible  head  of  water  and  be  of  such  a  nature  as  not 
to  require  the  use  of  experimental,  new  or  untried  methods  of  con- 
struction. If  terminal  lakes  are  to  be  formed,  the  dams  creating  them 
should  be  as  low  as  possible  imposing  the  minimum  weight  upon  the 
subsoil.  The  construction  of  even  a  low  barrage  at  the  Eio  Grande 
Delta  would  undoubtedly  encounter  innumerable  difficulties  in  cross- 
ing localities  where  the  sub-formation  would  be  such  as  to  give  way 
under  the  imposition  of  the  weight  of  material  placed  thereon.  The 
same  obstacle  would  probably  be  met  to  a  greater  or  less  extent  in  the 
construction  of  a  dam,  particularly  a  high  one,  in  the  vicinity  of 
Gatun.  The  entire  valley  to  at  least  a  depth  of  200  feet  is  alluvial. 
It  is  therefore,  highly  improbable  that  in  the  heterogeneous  mass  of 
material  with  which  the  ancient  gorge  is  filled,  particularly  near  the 
surface,  that  unforeseen  difficulties  in  securing  proper  foundation  would 
not  be  encountered. 

Mr.  Wallace  repeats  to  the  board  of  engineers  the  recommendation 
which  he  had  already  made  of  the  canal  commission,  that  no  temporary 
or  tentative  plan  should  be  adopted  that  will  interfere  with  the  final 
adoption  of  the  sea-level  plan. 

Mr.  Quellennec,  of  the  board  of  consulting  engineers,  at  a  board 
meeting  on  November  18,  1905,  explained  his  stand  in  favor  of  a  sea- 
level  canal,  stating  that  it  was  undeniable  that  a  sea-level  canal  is 
preferable  to  a  high-level  multi-lock  canal  both  with  a  view  to  safety 
and  to  facility  of  operation.  He  referred  to  his  experience  on  the  Suez 
Canal  which  has  convinced  him  of  the  advantages  offered  by  a  sea- 
level  canal.  In  spite  of  greater  time  and  cost,  he  believes  the  sea-level 
canal  at  Panama  should  be  constructed,  but  in  making  this  statement 

VOL.  XXLIV. — 28. 


434  THE   POPULAR   SCIENCE   MONTHLY 

he  does  not  wish  to  be  understood  as  saying  that  a  lock  canal  is  not 
practicable. 

At  the  same  meeting,  Mr.  Hunter,  of  the  Manchester  Canal,  gave 
expression  to  his  views  on  the  type  of  canal,  explaining  that  although 
as  a  member  of  the  Comite  Technique  he  favored,  under  the  circum- 
stances then  prevailing  a  lock  canal,  he  could  not  under  the  altered 
conditions  "  undertake  the  responsibility  of  joining  in  a  recommenda- 
tion to  the  United  States  for  the  construction  of  a  lock  canal.  .  .  ." 

Advocating  the  adoption  of  a  lock-canal  project,  on  the  other  hand, 
Mr.  Noble  said : 

I  believe  the  lock  canal  affords  quicker  construction,  that  the  wider  and 
deeper  waterways  it  provides  would  give  better  navigation;  that  the  transit 
of  ships  would  be  quicker  and  that  the  lock  canal  would  have  even  a  greater 
capacity  for  traffic  than  the  narrow  waterway  proposed  by  the  sea-level  canal 
committee. 

Another  advocate  of  the  lock  type  of  canal,  Mr.  Eipley,  concurred 
in  the  remarks  of  Mr.  Noble  and  gave  as  an  additional  reason  for 
his  position  the  belief  that  this  type  of  canal  would  provide  for  a  navi- 
gation the  limit  of  which  will  not  be  reached  in  a  number  of  years 
probably  40  to  75  years,  so  that  the  people  of  the  United  States  will 
not  soon  be  called  upon  to  make  additional  expenditures  for  improving 
the  canal ;  whereas  for  a  sea-level  canal  it  is  quite  probable  that  within 
a  short  time,  possibly  15  or  25  years,  a  widening  will  be  necessary  which 
will  cost  many  millions  of  dollars. 

Mr.  Parsons,  also  of  the  board  of  engineers,  referred  to  the  fact 
that  a  canal  was  to  be  built  for  all  time,  that  it  was  a  work  of  the 
greatest  constructive  magnitude  ever  undertaken.  The  plan  of  the 
canal  should  be  of  the  broadest  and  largest  possible  type  which  we  can 
conceive.  A  few  years  more  or  less  in  time  is  of  no  consequence. 
Neither  is  an  additional  cost  of  $50,000,000  or  even  $100,000,000  of 
importance,  as  there  will  be  an  adequate  return.  Accidents  similar  to 
those  which  have  occurred  on  the  Manchester  and  the  "  Soo  "  Canals 
have  occurred  also  in  the  Welland  and  other  canals.  These  accidents 
by  great  good  fortunes  have  not  been  disasters.  With  locks  of  large  size 

of  the  size  now  contemplated  the  results  would  have  been  more  serious.  It 
is  not  the  danger  to  the  ship  itself  that  I  have  in  mind,  .  .  .  but  the  danger 
to  the  canal.  If  at  one  of  these  big  locks  an  accident  should  happen,  such  as 
has  happened  at  other  locks  and  as  will  happen  here,  and  a  ship  should  go 
plunging  through  and  carry  away  the  safety  gates  and  every  other  mechanical 
device  for  protection,  releasing  the  lake  of  water  that  lies. behind  those  locks, 
the  section  of  the  canal  between  that  lock  and  the  ocean  terminas  would  be  so 
destroyed  that  it  would  take  anywhere  from  one  to  five  years  to  put  it  back  in 
service  again.  The  terminal  port  itself  would  be  gone,  the  canal  would  be  out 
of  use,  the  world's  traffic  would  be  deranged  and  the  difference  in  cost  of  the 
two  types  would  be  wiped  out  in  a  few  seconds  of  time.  That  risk  a  great 
government  can  not  be  justified  in  taking. 

With  these  views  before  him,  and  in  the  light  of  all  the  information 


THE   TYPE   OF   THE   PANAMA    CANAL  435 

then  at  his  command,  the  president  reached  the  conclusion  that  a  canal 
with  locks  would  best  fulfil  all  requirements,  and  says  in  transmitting 
the  hoard  report  to  the  Congress : 

In  my  judgment  a  lock  canal  as  herein  recommended  is  advisable.  If  the 
Congress  directs  that  a  sea-level  canal  be  constructed,  its  direction  will  of 
course  be  carried  out.  Otherwise  the  canal  will  be  built  on  substantially  the 
plan  outlined  in  the  accompanying  papers,  such  changes  being  made,  of  course, 
as  may  be  found  necessary,  including  possibly  the  change  recommended  by  the 
Secretary  of  War  as  to  the  site  of  the  dam  on  the  Pacific  side. 

"When  the  matter  was  before  the  senate  committee  on  inter-oceanic 
canals,  another  opportunity  was  provided  for  the  expression  of  views 
by  experts.  At  these  hearings,  Professor  Burr  said  that  he  was  as 
strongly  in  favor  of  the  sea-level  canal  as  he  ever  had  been. 

The  more  I  reflect  upon  it,  the  more  it  seems  to  me  that  that  plan  is  the 
one  which  the  United  States  Government  should  adopt. 

In  discussing  the  Gatun  dam,  which  is  a  feature  of  the  lock-canal 
project  as  adopted,  he  says: 

It  is  proposed  to  build  this  dam  by  simply  clearing  off  the  surface  material 
and  then  spreading  the  earth,  suitably  selected  from  the  canal  excavation,  in 
layers,  and  so  building  it  up  to  a  height  of  135  feet,  making  its  base  something 
like  half  a  mile  wide.3  In  my  judgment,  that  is  a  dangerous  experiment  on  a 
colossal  scale,  which  this  government  is  not  justified  in  undertaking. 

Continuing,  Professor  Burr  states  that  he  has  no  objection  to  earth 
dams  under  suitable  conditions  if  properly  designed  and  founded. 
Anything  like  a  flow  of  water  through  the  permeable  material  under  the 
dam  should  be  prevented.  No  suitable  means  for  accomplishing  this 
are  provided  in  this  design.  He  indicates  measures  that  are  ordinarily 
taken  to  check  the  flow  of  water  under  a  dam,  and  instances  several 
failures  of  earth  dams.  In  speaking  of  the  dams  near  LaBoca  resting 
against  Sosa  Hill,  the  construction  of  which  was  subsequently  under- 
taken, but  owing  to  the  yielding,  unstable  character  of  the  marsh  lands 
on  which  they  were  to  rest,  have  been  abandoned,  Professor  Burr  says : 

The  dams  on  the  Pacific  side  are  smaller,  and  the  risks,  perhaps,  may  be 
of  less  magnitude;  but  they  are  of  the  same  character,  and  there  is  the  same 
objection  to  them,  in  my  opinion,  This  dam  between  LaBoca  and  the  high 
ground  opposite  would  be  founded  largely  upon  the  most  slippery  kind  of  mud. 
Any  one  who  has  been  there  and  has  seen  the  bottom  of  the  Rio  Grande  estuary 
exposed  at  low  tide,  I  think  will  agree  with  me  that  it  is  a  very  lubricating 
material;  and  if  you  were  to  put  a  bank  of  earth  on  it,  even  if  it  were  half  a 
mile  thick,  I  think  it  would  be  in  great  danger  of  being  pushed  out  bodily. 

Rftncccft  t-ferwv 
In  speaking  of  the  operation  of  locks,  he  calls  attention  to  the  fact 

that  the  experience  at  the  lock  at  St.  Mary's  Falls  is  not  a  safe  guide 
for  reaching  conclusions  regarding  the  safety  of  six  such  locks  as  will 
be  required  for  the  Panama  Canal.  Their  lift  is  50  per  cent,  greater, 

8  As  now  contemplated,  the  dam  is  to  be  constructed  by  the  hydraulic  fill 
method. 


43  6 

and  the  dangers  increase  at  a  more  rapid  rate  than  proportional  to  the 
lift,  and  the  dangers  are  magnified  by  the  fact  that  the  locks  are  to  be 
in  flights.  He  furthermore  reaches  the  conclusion  that  the  traffic  capa- 
city of  the  lock  canal  should  be  estimated  at  about  35,000,000  tons  per 
annum  instead  of  at  80,000,000  tons,  the  figure  assumed  by  the 
minority. 

An  extended  and  comprehensive  argument  for  a  sea-level  project 
was  presented  to  the  senate  committee  by  General  Davis,  who,  as  a 
member  of  the  commission  of  1904,  and  resident  on  the  isthmus  as 
governor  of  the  Canal  Zone  for  a  year,  and  thereupon  as  chairman  of 
the  board  of  consulting  engineers,  had  had  unusual  opportunity  for 
arriving  at  a  mature  conclusion.  All  that  General  Davis  said  in  rela- 
tion to  the  type  of  the  canal  before  the  committee  should  be  read  by 
those  who  desire  to  follow  this  matter  farther.  Short  extracts,  and  a 
condensed  statement  embodying  the  substance  of  his  presentation,  can 
alone  be  here  attempted. 

What  the  situation  demands  is  well  known,  and  the  American  government 
has  declared  to  the  world  that  the  obstacle  at  Panama  shall  be  removed.  Will 
it  be  removed  if  we  leave  a  hill  over  which  the  world's  commerce  and  navies 
are  to  be  hoisted?  Will  the  world  consider  that  we  have  adequately  solved  the 
problem,  and  will  the  American  people  be  satisfied  with  the  result  if  we  offer 
them  anything  inferior  as  respects  capacity,  or  convenience,  or  adaptability  for 
enlargement,  or  type,  to  what  capital  did  for  the  old  world — a  canal  which  now 
serves  as  a  model,  and  will  continue  to,  until  we  acquit  ourselves  of  the  respon- 
sibility voluntarily  and  eagerly  assumed. 

General  Davis  compares  the  Soo  Canal,  with  its  few  thousand  feet 
of  channel  approaches,  to  the  great  tidal  harbor  basins  of  Europe.  It 
is  more  nearly  analogous  to  these  than  to  a  great  interoceanic  canal  on 
which  the  aggregate  length  of  locks  alone  ex«eedg  by  nearly  a  mile  the 
entire  length  of  the  £>oo  Canal.  BecausexLaKfenuro5^'is  twenty  odd 
feet  higher  than  La&e  Er^it  was  useless  to  hope  for  a  channel  clear 
of  all  obstructions,  and  American  and  Canadian  engineers  have  provided 
the  best  solution  possible. 

At  first,  locks  350  feet  long  sufficed.  Then  one  515  feet  long  was  added. 
Next,  the  first  were  demolished  and  replaced  with  a  lock  with  a  chamber  800 
feet  long.  Then  the  Canadians  made  another  in  their  territory  900  feet  long; 
and  we  are  about  to  demolish  our  second  lock  to  put  in  one  1,400  long.  .  .  . 
The  critics  of  the  majority  report  admit  that  a  canal  at  sea-level  would  have 
certain  advantages.  I  think  it  may  be  said  that  one  and  all  concede  that  if  a 
sea-level  waterway  be  wide  and  deep  enough,  it  would  be  superior  to  any  in- 
volving excavated  lakes,  locks  and  lifts;  but  they  discard  it  as  impracticable 
because  of  the  greater  cost. 

The  better  approach  to  the  straight  line  requirement  by  the  sea-level 
canal  is  pointed  out.  The  lock  canal  project  shows  21  per  centum  more 
winding  and  tortuous  navigation  than  the  sea-level  project.  General 
Davis  estimates  the  expense  of  maintenance  and  operation  of  a  sea-level 
canal  at  $1,550,000  per  annum,  and  the  lock  type  of  canal,  at  $2,- 


THE  TYPE  OF  THE  PANAMA  CANAL 


437 


150,000.  The  cost  of  the  government  of  the  Canal  Zone,  estimated  at 
$100,000  is  not  included  in  these  figures.  Eelating  to  dimensions,  and 
other  features  of  various  canals,  data  were  presented  in  tabular  form,  in 
part  as  here  reproduced. 


EXISTING  AND  PKOPOSED  CANALS 


Units 

Panama 
Sen-level 

Panama 
Lock 

Suez  Now 

Suez 
Enlarged 

Kiel 

Total  length  

Miles 

49.35 

49.72 

94.76 

94.76 

57.89 

Straight  portion  
Curved  portion  
Curved  portion  
Depth  

Miles 
Miles 
Per  cent. 
Feet 

30.18 
19.17 

38.8 
40 

42.25 
7.46 
15.0 
40 

81.73 
13.04 
13.8 
31  2 

81.73 
13.03 
13.8 
34.4 

40.9 
29.52 

Least  bottom  width 
Least  bottom  width 
in  curves  

Feet 
Feet 

150 
150 

200 
250 

108.26 
131 

147.63 
160* 

72.17 
75.2 

Least  cross-section.. 
Total  curvature  

Sq.  feet 
Degrees 

8,160 
597 

8,160 
637 

/  5,813 
\  6,025 
467 

f  7,741 
\8,144 
467 

4,444 

Curves  _ 

Number  of 

19 

24 

15 

15 

26 

Locks  

Number  of 

j 

6 

0 

0 

2 

Locks,  length  

Feet 

1,000 

900 

492 

Locks    width  

Feet 

100 

90 

82 

*  Approximate. 

The  enlargement  of  the  Suez  Canal  is  not  yet  complete.  The  total 
length  of  the  Suez  Canal  is  104.8  statute  miles,  of  which  about  10 
miles  are  in  lake,  leaving  the  length  of  the  excavated  channel  94.76 
miles. 

The  total  length  of  the  Kiel  Canal  is  60.89  miles,  of  which  3  miles 
are  in  lakes.  Where  two  sets  of  figures  are  noted  for  the  area  of  the 
cross-section,  one  applies  to  low,  the  other  to  high  water. 

General  Davis  shows  that  the  proposed  sea-level  canal  will  not  be 
dangerous,  narrow  or  contracted,  because  this  is  not  true  of  the  Suez 
Canal,  which  is  longer,  narrower  and  shallower,  and  has  more  abrupt 
bends  than  the  canal  proposed  by  the  majority  of  the  engineers.  He 
calls,  attention  to  the  fact  that  in  the  opinion  of  very  able  engineers 
the  cost  in  time  will  be  but  slightly  more  for  the  channel  at  ocean  level, 
than  for  a  canal  with  a  summit  level  at  85  feet ;  and  he  says : 

It  is  certain  that  the  cost  in  money  of  the  simple  low-level  channel  in 
which  every  existing  and  projected  vessel  would  find  convenient  passage,  will 
cost  some  tens  of  millions  more  than  the  complicated  high-level  structures,  but 
the  former  will  closely  approach  and  ultimately  result  in  the  ideal,  simple 
natural  waterway  .  .  .  while  the  latter  will  stand  for  the  opposite  until  heroic 
measures  are  resorted  to  and  the  objectionable  structures  are  removed,  for  the 
idea  of  transformability  is  eliminated  by  the  majority. 

Col.  Oswald  H.  Ernst,  of  the  Engineer  Corps,  TJ.  S.  Army,  a  mem- 
ber of  the  canal  commission  of  1905,  said  in  part: 

I  have  made  a  very  careful  review  of  the  arguments  presented  on  both  sides, 
as  exhibited  in  these  two  reports  which  you  have  before  you — the  majority  and 
the  minority  reports — and  I  am  satisfied  that  the  United  States  will  get  a 


438  THE   POPULAR   SCIENCE   MONTHLY 

perfectly  satisfactory  canal  in  very  much  less  time,  and  for  very  much  less 
money,  under  the  plan  proposed  by  the  minority.  I  believe  that  the  canal  under 
that  plan  will  cost  little  more  than  half  what  the  canal  of  the  majority  will 
cost,  and  the  time  will  be  a  little  more  than  half,  and  when  done  it  will  be  a 
better  canal,  because  it  will  be  three  times  as  big  a  canal.  The  volume  of  water 
in  the  sea-level  canal  is  only  one  third  what  the  volume  of  water  is  in  the 
lock  canal.  Leave  out  everything  in  those  lakes  beyond  the  width  of  1,000  feet, 
and  everything  beyond  a  depth  of  45  feet,  and  you  have  three  times  the  number 
of  cubic  yards  of  water  in  the  lock  canal  that  you  have  in  the  sea-level  canal. 

Among  the  earliest  and  best-informed  advocates  of  the  lock  canal 
is  General  Henry  L.  Abbot,  of  the  Corps  of  Engineers,  U.  S.  Army 
(retired),  who  was  a  member  of  the  Comite  Technique,  and  was  also  a 
member  of  the  board  of  consulting  engineers.  General  Abbot  has  been 
a  close,  able  and  careful  student  of  the  hydraulic  and  other  problems 
involved,  and  ever  since  the  days  of  the  Comite  Technique  has  con- 
tributed much  to  the  discussion  thereof.  In  presenting  his  views  to  the 
board  of  consulting  engineers,  which  are  at  too  great  length  to  be 
quoted  in  full,  he  says: 

The  most  important  consideration,  from  an  engineering  point  of  view,  in 
projecting  a  transit  route,  whether  a  railroad  or  a  canal,  is  to  adjust  the  details 
to  the  topography  and  natural  conditions  of  the  region  to  be  traversed.  On  the 
Isthmus,  the  Chagres  River  is  the  dominating  feature.  .  .  .  The  deep  excavation 
in  the  Culebra  section  is  a  formidable  undertaking,  chiefly  because  it  will  be 
necessary  to  transport  the  soil  to  long  distances;  but  once  executed,  it  will 
remain  without  giving  occasion  for  anxiety  in  the  future.  The  Chagres  is 
capable  of  becoming  a  very  active  enemy  at  any  future  time,  unless  effectively 
tamed  by  good  engineering  methods. 

General  Abbot  thereupon  discusses  the  peculiarities  of  this  river, 
and  its  relation  to  the  several  canal  projects.  He  reaches  the  conclusion 
that  the  problem  of  the  control  of  the  Chagres  is  solved  by  the  lock 
canal  project  in  a  manner  at  once  vastly  better  and  vastly  more  simple 
than  by  the  sea-level  project.  He  expresses  his  judgment,  however,  that 
the  primary  consideration  in  choosing  between  the  two  projects  "  should 
be  their  relative  merits  as  routes  for  shipping.  The  elements  of  time 
and  cost  are  secondary,  but  too  important  to  be  neglected."  According 
to  General  Abbot,  double  the  cost  and  double  the  time  should  be  allowed 
for  the  completion  of  a  sea-level  canal,  and  when  completed,  the  canal 
would  be  distinctly  inferior  to  a  canal  with  locks.  In  the  matter  of  the 
sufficiency  of  the  flow  of  Chagres  Eiver  to  maintain  the  lake  above  the 
Gatun  dam,  at  the  desired  elevation,  General  Abbot  is  emphatically  of 
the  opinion  that  the  water  supply  will  be  adequate.  Based  on  a  most 

Cub'c  Feet 
per  Second 

Evaporation  loss,  estimated  710 

Leakage  of  gates  250 

Infiltration   77 

For  light,  power,  etc 200 

Contingencies   200 

Total    M37 


TEE  TYPE  OF  THE  PANAMA  CANAL      439 

careful  study  of  all  existing  data,  on  the  assumption  that  the  water 
surface  of  the  lake  will  have  an  area  of  110  square  miles,  he  gives  the 
following  figures: 

The  water  available  is  estimated  at  not  less  than  1,225  cubic  feet 
per  second  natural  flow  at  Gatun  during  the  three  months  of  lowest 
river  stage,  and  to  this  amount  there  are  to  be  added  an  additional 
volume  of  1,577  cubic  feet  per  second,  resulting  from  a  four  feet  allow- 
able fluctuation  of  the  lake  surface.  There  are  then  2,802  cubic  feet 
per  second  available,  of  which  the  difference  between  2,802  and  1,437, 
or  1,365  cubic  feet  per  second,  will  be  available  for  lockages.  This 
amount  of  water,  according  to  General  Abbot,  will  be  adequate  for  26 
daily  transits.  Should  there  be  need  for  more  stored  water,  the  same 
can  be  secured  by  the  construction  of  a  dam  at  Alhajuela,  where  suffi- 
cient water  can  be  impounded  to  increase  the  number  of  lockages  by 
40,  though  only  27  have  been  assumed  by  the  minority. 

It  is  absolutely  certain  that  there  can  be  no  deficiency  of  water  for  any 
conceivable  traffic  demands. 

Since  the  foregoing  estimates  were  made  it  has  been  found  that  the 
Gatun  Lake  will  have  a  surface  area  of  about  164  square  miles,  instead 
of  110,  as  assumed.  The  lock  dimensions  have  also  been  increased,  as 
explained,  and  more  water  will  be  required  for  each  transit  through 
the  canal.  The  estimates  relating  to  the  available  water  supply  as  above 
quoted  therefore  need  revision. 

And  thus,  in  the  light  of  the  information  then  available,  the  type 
of  the  canal  was  fixed  in  1906  by  action  of  the  Congress  of  the  United 
States  in  substantial  conformity  with  the  recommendation  of  the  minor- 
ity of  the  board  of  engineers,  and  for  three  years  the  work  of  construc- 
tion has  been  actively  pushed. 

The  progress  that  has  been  made  is  clearly  set  forth  in  the  records 
of  work  done.  Measured  by  cubic  yards  of  excavation  it  has  been 
highly  satisfactory.  The  graphical  presentation  herewith  is  from  a 
recent  summary  published  by  the  Engineering  News.  It  appears  from 
the  figures  compiled  for  that  summary  that  the  total  excavation  since 
the  canal  became  the  property  of  the  United  States  at  the  close  of  the 
year  1908,  amounted  to  59,980,000  cubic  yards,  of  which  53,161,000 
cubic  yards  had  been  taken  out  of  the  canal  prism,  and  6,819,000  cubic 
yards  were  excavated  from  the  locks  and  spillway  sites  and  from  other 
points  outside  of  the  canal  proper.  Of  the  total  work,  that  done  by 
steam  shovels  (work  in  the  dry)  amounted  to  37,155,000  cubic  yards, 
and  dredges  had  excavated  22,825,000  cubic  yards. 

It  has  been  estimated  by  the  canal  commission  that  the  total  exca- 
vation to  complete  the  canal  on  the  lines  of  the  accepted  project  (not 
including  the  work  by  the  French  canal  companies)  is  142,000,000 
cubic  yards.  According  to  these  figures  there  were  about  89,000,000 
cubic  yards  yet  to  be  removed  from  the  canal  prism  on  January  1, 1909. 


440  THE   POPULAR   SCIENCE   MONTHLY 

It  should  be  noted,  however,  that  there  has  been  little  deepening  of 
the  canal  excavation  on  the  backbone  of  the  isthmus,5  at  and  near 
Culebra  below  the  levels  reached  by  the  French  companies.  The  work 
thus  far  has  required  the  widening  of  the  cut.  Whether,  hereafter, 
under  the  requirement  for  securing  depth  the  same  rate  of  progress  can 
be  maintained,  as  now  shown  by  the  records,  is  a  question  which  can 
best  be  answered  by  the  engineers  now  in  charge  of  the  work.  It  is 
probable  that  the  future  records  will  show  a  gradually  decreasing  rate 
of  progress  if  measured  by  yards  of  excavation  only. 

When  the  building  of  the  dams  contemplated  by  the  minority,  from 
high  ground  at  Corozal  to  Sosa  Hill,  was  undertaken,  it  was  soon  found 
that  these  structures  were  ill-advised.  The  muck  and  mud  of  the 
"  Manglares  "  could  not  support  the  load  of  a  moderate  fill.  There 
was  much  settling  and  lateral  displacement  and  the  work  was  aban- 
doned. This  was  in  no  wise  fatal  to  the  lock  project,  because  it 
merely  involved  the  shifting  of  the  proposed  locks  at  Sosa  Hill  back  to 
Miraflores,  where  excavation  for  them  is  now  in  progress. 

The  work  on  the  main  dam,  the  dam  at  Gatun,  has  barely  com- 
menced. This  dam  will  be  of  earth;  it  will  have  a  crest  length  of 
about  7,000  feet,  and  a  breadth  of  base,  measured  up  and  down  stream, 
of  nearly  one  half  mile.  The  greater  part  of  the  material  of  which  the 
dam  is  to  be  composed  will  be  put  in  place  by  the  hydraulic  method. 
The  material  will  be  transported  by  water  in  pipes,  and  a  practically 
impervious  and  safe  body  of  earth  will  thus  be  deposited  across  the 
valley  of  the  Chagres  at  Gatun.  The  recent  settling  and  slipping  of  a 
rock  fill  that  was  being  placed  along  the  up-stream  toe  of  the  proposed 
structure  is  of  no  great  significance.  There  will  be  other  slips  until 
displacement  of  layers  of  yielding  material,  under  and  particularly  near 
the  edges  of  such  fills,  is  sufficient  to  secure  stability.  The  doubts  con- 
cerning the  feasibility  of  a  structure  at  this  point  have  not  arisen  from 
fear  of  such  slips,  but  from  the  uncertainty  relating  to  a  movement  of 
water  at  considerable  depth  under  the  dam  in  porous  deposits,  the  ex- 
tent and  permeability  of  which,  notwithstanding  information  obtained 
by  borings  and  shafts,  must  necessarily  remain  more  or  less  conjectural. 
It  is  feared  by  some  that  such  underflow  may  threaten  the  safety  of  the 
dam  and  by  others  that  a  serious  loss  of  water  may  thus  result. 

All  such  fears  are  far-fetched.  There  is  but  little  basis  for  them. 
There  can  be  no  injury  to  the  dam  from  a  moderate  underflow  if  suit- 
able precautions  are  taken  to  let  the  water  come  to  the  surface  at  the 
down-stream  toe  of  the  dam  through  sand,  gravel  and  broken  rock 

8  Information  is  published  in  the  Canal  Record  of  February  10,  1909,  that 
the  President  in  October,  1908,  authorized  the  widening  of  the  Culebra  section 
of  the  canal  from  200  feet  on  the  bottom  to  300  feet.  This  fact  was  not  known 
when  the  above  was  written.  The  process  of  widening  without  materially 
increasing  the  average  depth  of  this  section  of  the  canal  may  be  expected  to 
continue,  therefore,  some  time  longer. 


THE   TYPE    OF   THE   PANAMA    CANAL  441 

deposits,  so  that  it  can  not  displace  the  earth  particles  with  which  it 
conies  in  contact  in  its  passage  under  the  dam.  To  make  a  convincing 
estimate  of  the  volume  of  flow  in  the  porous  sub-surface  strata  under 
the  dam  is  almost  out  of  the  question,  because  the  extent,  character 
and  continuity  of  these  strata  can  not  be  definitely  ascertained,  and 
it  will  be  difficult,  if  not  impossible,  to  determine  at  what  point 
or  points  the  water  will  sink  from  the  lake  above  the  dam  into 
these  layers.  The  engineers  can,  therefore,  do  no  better  than 
make  unfavorable  assumptions  and  determine  the  maximum 
water  loss  that  may  result  under  such  hypotheses.  There  is  no  proba- 
bility that  this  will  be  such  as  to  prove  embarrassing  to  the  project. 
It  is  to  be  remembered  in  this  connection  that  nearly  always,  when  a 
subsurface  flow  in  a  river  channel  has  been  developed  by  the  construc- 
tion of  a  subsurface  curtain  or  dam,  the  result  in  water  output  has  been 
disappointing.  In  other  words,  the  probability  is  that  the  under-flow 
will  be  over-estimated.  Nevertheless,  the  public  seems  to  expect  further 
assurance  that  the  canal  work  is  progressing  along  proper  lines,  par- 
ticularly as  it  now  appears  probable  that  the  cost  of  the  lock  canal  will 
be  more  than  double  the  amount  named  by  the  board  of  engineers  in 
comparing  the  cost  of  the  two  types  of  canal. 

In  the  writer's  opinion,  it  may  confidently  be  assumed  that  a  safe 
dam  can  be  constructed  at  Gatun.  The  situation  at  Gatun  is,  there- 
fore, of  minor  importance  in  the  further  discussion  of  the  question  that 
has  again  arisen:  "Would  it  not  still  be  well  to  change  the  approved 
project  and  to  complete  the  excavation  to  sea-level?"  This  question, 
if  it  be  again  opened,  will  have  to  be  considered  in  the  light  of  the 
views  of  the  experts  whose  opinions  have  been  herein  referred  to,  in  the 
light  of  the  work  already  done  and  the  progress  already  made;  in  the 
light  of  the  experience  on  the  isthmus  during  nearly  five  years  of  effect- 
ive work,  and  in  the  light  of  such  additional  facts  and  conclusions  as 
may  be  submitted  by  the  engineers  now  about  to  start  for  the  isthmus. 

January  25,  1909. 


